1. Field of the Invention
The present invention relates to agricultural implements, and, more particularly, to agricultural tillage implements.
2. Description of the Related Art
Farmers utilize a wide variety of tillage implements to prepare soil for planting. Some such implements include two or more sections coupled together to perform multiple functions as they are pulled through fields by a tractor. For example, a field cultivator is capable of simultaneously tilling soil and leveling the tilled soil in preparation for planting. A field cultivator has a frame that carries a number of cultivator shanks with shovels at their lower ends for tilling the soil. The field cultivator converts compacted soil into a level seedbed with a consistent depth for providing excellent conditions for planting of a crop. Grass or residual crop material disposed on top of the soil is also worked into the seedbed so that it does not interfere with a seeding implement subsequently passing through the seedbed.
Tillage equipment prepares the soil by way of mechanical agitation of various types, such as digging, stirring, and overturning. Examples of which include ploughing (overturning with moldboards or chiseling with chisel shanks), rototilling, rolling with cultipackers or other rollers, harrowing, and cultivating with cultivator shanks.
Tillage is often classified into two types, primary and secondary. There is no strict definition of these two types, perhaps a loose distinction between the two is that tillage that is deeper and more thorough is thought of as primary, and tillage that is shallower is thought of as secondary. Primary tillage such as plowing produces a larger subsurface difference and tends to produce a rough surface finish, whereas secondary tillage tends to produce a smoother surface finish, such as that required to make a good seedbed for many crops. Harrowing and rototilling often combine primary and secondary tillage into one operation.
Wheels are often integral with tillage implements and are used for both transportation of the implement, and for depth control of the tilling elements. The prior art includes control systems that raise and lower the implement as an entire unit, which can result in uneven tillage across the implement width of today's wider equipment. What is needed in the art is an easy to use mechanism for depth control and levelling of an agricultural tillage implement.